Set baseurl to empty string.

The rendered site is going to be deployed without a baseurl, but
we use {{ site.baseurl }} in case that ever changes.  By default
baseurl is set to '/' which results in a two consecutive slashes
in links.

See
http://jekyllrb.com/docs/github-pages/index.html#project_page_url_structure
Use rugged 0.16.0 since that is what Openshift has.
Refactor date_modified functionality.

Rather than monkey patching Jekyll's Page class, use a Liquid
tag to do the same thing.
Add silly plugin to fix Jekyll output.
Add favicon.
Since we aren't deploying on github pages, we don't need their gem.
Remove useless begin/end. Print error in red.